1. Field Of The Invention
The invention relates to a new process for the production of malonic acid anhydride.
2. Background Art
Malonic acid anhydride is a reactive structural element for the production of numerous active ingredients for pharmaceutical agents, pesticides or dyes (see U.S. Pat. Nos. 4,251,447 and 4,360,691). Ozonizations of diketene to malonic acid anhydride are known. Perrin, in U.S. Pat. Nos. 4,251,447 and 4,360,691, claims the production of malonic acid anhydride or malonic acid anhydride derivatives by the reaction of diketene at 0.degree. to -100.degree. C. with ozone. But a drawback of this process, serious for safety reasons, is that insoluble formaldehyde-peroxide polymers result as a by-product in organic solvents (U.S. Pat. No. 4,360,691, column 5, lines 3 to 5), which, e.g., are highly explosive according to Lapalme et al., Can. J. Chem., Vol 57, (1979), page 3272.